Impact

Prevalence of obesity and overweight in Australia

Adults

Nearly two-thirds (63.4%) of Australians aged 18 and over were overweight or obese in 2014-15.[1] The prevalence of overweight and obesity has increased significantly from 56.3% in 1995. More men than women were overweight or obese in 2014-15 (70.8 vs 56.3%) with rates increasing with age in both sexes.[1] Women living in areas of most disadvantage were more overweight or obese than women living in areas of least disadvantage (61.1% vs 47.8%).[1] There were no differences between areas of disadvantage for men. Overweight and obesity are also more common in regional areas of Australia than major cities.[1]

Children

The prevalence of overweight in Australian children doubled from the mid-1980s to the mid-1990s and rates of obesity have trebled.[2][3] Since then levels have continued to increase, but at a slower rate.[4] Over a quarter (27.4%) of children aged 5-17 years were overweight or obese in 2014-15.[1]

Obesity in childhood significantly increases the risk of being obese in adulthood.[5]

Indigenous Australians

Two-thirds (66%) of Indigenous people aged 15 years and over were overweight or obese in 2012-13.[6] While the combined overweight/obesity rates for Indigenous people aged 15 years and over are similar to those for non-Indigenous people, the obesity rates are significantly higher in this population. Indigenous people are 1.5 times as likely as non-Indigenous people to be obese.[6] This difference is more marked in women.[6][7]

Nearly 30% of Indigenous children aged 2–14 were overweight or obese[6] and are 1.2 times as likely to be overweight/obese as non-Indigenous children.[8]

Diet and physical activity are both important for maintaining a healthy weight. However, diet is the more important factor. Research shows that physical activity plus calorie restriction achieves virtually the same result in weight loss as calorie restriction alone.[9]

What are Australians eating?

Adults

The 2011–13 Australian Health Survey found the average adult male consumed 9,655 kilojoules of food and beverages and the average adult female consumed 7,402 kJ.[10] On average, just over one-third (35%) of total daily energy reported as consumed was from 'discretionary foods' i.e. foods and drinks not necessary to provide nutrients.[10] The 2014-15 Australian National Health Survey reported that 49.8% of Australians adults met the guidelines for recommended intake of fruit, however only 12% met the guidelines when fruit juice and dried fruit are excluded.[1] Only 7.0% of Australians met the guidelines for intake of vegetables.[1] Women were more likely to meet the guidelines than men. In general, older people were more likely to meet the guidelines than younger people.[1]

Children

In 2014-15, 68.1% of children aged 2-18 years met the guidelines for recommended daily serves of fruit, while 5.4% met the guidelines for serves of vegetables.[1] Girls were more likely than boys to meet recommended intakes for fruit but the proportions of girls and boys meeting recommended intakes for vegetables were similar.[1] In 2012-13, the National Secondary School Diet and Activity Survey (NaSSDA) reported that 40% of students consume fast food at least once a week. Boys were more likely than girls to report eating fast food on a weekly basis.[11]

Indigenous Australians

The 2012–2013 Aboriginal and Torres Strait Islander Health Survey, found only 5% Indigenous people aged 15 years and over met the guidelines for recommended intake of vegetables.[6] Less than half (43%) met the guidelines for recommended intake of fruit.[6] This proportion was slightly less than that of non-Indigenous Australians.[6]

How physically active are Australians?

Adults

The 2014-15 Australian National Health Survey found that 55.5% of 18-64 year olds participated in sufficient physical activity in the last week.[1] The Department of Health recommends adults accumulate 150 to 300 minutes of moderate intensity physical activity or 75 to 150 minutes of vigorous intensity physical activity each week.[12] Nearly one in three (29.7%) were not sufficiently active (less than 150 minutes), while 14.8% were inactive (no exercise in the last week).[1] Similar proportions of men and women were inactive in 2014-15 (15.2% and 14.4% respectively).[1]

Children

The 2011–2012 Australian Health Survey revealed that just over 60% of children aged 5-17 years met the guideline of at least 60 minutes of physical activity per day. Only one in five (19%) met the guideline on all seven days prior to the survey.[13] In general, physical activity decreased with age.[13]

Indigenous Australians

The 2012–13 Aboriginal and Torres Strait Islander Health Survey reported that three in five (62%) Indigenous adults were physically inactive.[6] Just over one-quarter (28%) of Indigenous adults had exercised at a moderate level, and one in ten (10%) at a high level.[6] Indigenous men were more likely to exercise than women.[6]

Compared with non-Indigenous Australians, Indigenous adults were more likely to be sedentary or to exercise at low intensity, less likely to participate in high intensity exercise and less likely to meet physical activity guidelines.[6]

Impact of diet, physical inactivity and obesity on cancer in Australia

Australia’s adult obesity rate is the fifth highest among OECD countries.[14] Adult obesity rates in Australia have nearly tripled in the last 30 years, and if effective interventions are not put in place it is estimated that 7.2 million Australians (34% of the projected population), will be obese by 2025[15]

Overlaps in obesity and overweight, and other lifestyle-related risk factors make it difficult to quantify their specific impact on cancer burden. For example, physical inactivity and low fruit and vegetable consumption are independent cancer risk factors, but they also contribute to high body mass, which is another risk factor.

Australian analyses have shown that overweight and obesity and physical inactivity and poor nutrition are responsible for a significant proportion of the cancer burden in Australia[16][17][18][19], second only to tobacco smoking.[20] It was estimated that 3.4% (3,917 cases) of all cancers diagnosed in 2010 were attributable to overweight/obesity[16], 1.6% (1,814 cases) to insufficient physical activity[17], 4.0% (4,475 cases) to inadequate intake of fruit, non-starchy vegetables and dietary fibre, and 2.3% (2,614 cases) to consumption of red and processed meat.[19]

Health and economic impact

In 2011, high body mass accounted for 5.5% of Australia’s total burden of disease.[21] The disease burden attributable to physical inactivity was estimated to be 5.0%, while dietary factors, including low consumption of fruit, vegetables and fibre, and high consumption of red and processed meat, accounted for 6.0% of Australia’s total burden of disease.[21]
The total cost of obesity in Australia in 2011-12 was estimated to be $8.6 billion (in 2014-15 dollars), including $3.8 billion in direct costs (including GP, specialist services, hospital care, pharmaceuticals, and public health interventions) and $4.8 billion in indirect costs (including absenteeism, government subsidies and forgone tax).[22]The direct costs of obesity alone were equivalent to approximately 2.6% of national spending on healthcare in 2011-12.[22]

In Australia, healthcare expenditure has been shown to increase with BMI.[23] For adults with a BMI between 30 and 35 and those with a BMI higher than 35 annual health spending is 19% and 50% higher respectively than that of normal weight individuals.[23]